Standing Sound Waves - Two Sources


To demonstrate the origin of standing waves from two identical sources.


Audio oscillator, two small speakers and microphone on optical rail, audio amplifier, and dual trace oscilloscope.

Setup Time

10 min.




Both speakers are driven by the same 3000 Hz sine wave from the audio oscillator, which is shown on the◙top trace of the oscilloscope. The standing wave pattern, observed by sliding a microphone along the optical rail between the speakers, is displayed on the lower trace.◙


Robert R. Meijer, Demonstrations on Standing Sound Waves, AJP 16, 360, (1948). ◙Francis W. Sears, Measurement of the Wavelength of Sound Wave, TPT 3, 79, (1965). ◙S. S. Lesty, A Method for Measuring the Sound Wavelength in Gases, AJP 31, 996-98, (1963). ◙J. Rekveld, On the Teaching of "Stand Waves," AJP 26, 159-163, (1958). ◙Directions For Use of Small Speaker, Leybold Heraeus 58006.